It is required for lenses of recent date utilized for a monitoring purpose or for a vehicle-installation purpose to have a wide angle and a high resolution. Regarding such wide-angle lenses, in order to achieve a high resolution, a configuration has been proposed, which is provided with a joined lens on the image side relative to a diaphragm so as to reduce spherical aberration (see Patent Literatures 1, 2, 3, and 4). Furthermore, in Patent Literatures 3 and 4, a configuration which is further provided with a joined lens on the object side relative to the diaphragm is proposed.